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2004 Chevrolet Trailblazer

Owner reports · Recalls · Investigations

More warning signs than most Trailblazer years

Owner complaints for the 2004 Chevrolet Trailblazer are substantially higher than the model-year median of 87.5.

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When problems were reported

Mileage at the reported incident

899 reports with mileage · 182 unknown

NHTSA’s mileage field refers to the reported incident, not necessarily the filing date. This shows report counts, not the likelihood of a failure.

What to inspect

Issues worth paying extra attention to based on owner reports.

  • Electrical System. Review the 627 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
  • Exterior Lighting. Review the 101 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
  • Fuel System, Gasoline. Review the 93 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →

NHTSA owner reports · September 18, 2026 snapshot.

56 crash reports31 fire reports47 injury reports

Equipment complaints

11 reports
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42,000 miles · Feb 7, 2011
EquipmentUnknown Or Other

FAILURE OF THE GAUGE CLUSTER ON A 2004 CHEVY TRAILBLAZER CURRENTLY WITH 59,300 MILES. ABOUT JUNE 2009 THE TACH CONTINUALLY READ INCORRECTLY. DEALER TRIED TO MISLEAD ME TO BRING IT IN FOR A DIAGNOSIS AT A COST OF APPROX. $100 I TOLD THEM ITS BROKE WHY SHOULD I PAY FOR A DIAGNOSIS. I HAD READ ABOUT THE PROBLEM ON -LINE AT EDMUN…

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FAILURE OF THE GAUGE CLUSTER ON A 2004 CHEVY TRAILBLAZER CURRENTLY WITH 59,300 MILES. ABOUT JUNE 2009 THE TACH CONTINUALLY READ INCORRECTLY. DEALER TRIED TO MISLEAD ME TO BRING IT IN FOR A DIAGNOSIS AT A COST OF APPROX. $100 I TOLD THEM ITS BROKE WHY SHOULD I PAY FOR A DIAGNOSIS. I HAD READ ABOUT THE PROBLEM ON -LINE AT EDMUNDS,COM.,MY SUV HAD 41,000 TO 42,000 MILES ON IT. IN JULY 2010 MY GAS GAUGE STARTED TO OCCASIONALLY MALFUNCTION, NOW JAN. 2011 IT IS INCORRECT. IN NOV. 2010 MY CHARGING GAUGE STARTED MALFUNCTIONING. I ALSO HAVE SINCE READ ONLINE OF THE SAME PROBLEM ON OTHER SIMILAR YEAR GM TRUCKS ANS SUV AND THEY HAVE RECALLS ON THEM. ITS JUST A MATTER OF TIME FOR THE SPEEDOMETER GAUGE TO READ INCORRECTLY. PLEASE HELP, THESE MALFUNCTIONS ARE NOT SAFE. *LN

NHTSA ODI #10380964

77,200 miles · Apr 1, 2010
Equipment

ALL OF MY GAUGES ON MY DASHBOARD COMPLETELY TURN OFF AND THEN RANDOMLY TURN BACK ON. IT IS VERY DANGEROUS TO DRIVE AROUND WITH NO SPEEDOMETER, GAS GAUGE, OLIL, BATTERY, TACHOMETER OR ODOMETER ON. THEN IT ALL OF A SUDDEN WILL TURN ON. IT NEEDS TO BE RECALLED. I TOOK IT TO A REPAIR SHOP AND THEY SAID IT WOULD COST AROUND $500 …

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ALL OF MY GAUGES ON MY DASHBOARD COMPLETELY TURN OFF AND THEN RANDOMLY TURN BACK ON. IT IS VERY DANGEROUS TO DRIVE AROUND WITH NO SPEEDOMETER, GAS GAUGE, OLIL, BATTERY, TACHOMETER OR ODOMETER ON. THEN IT ALL OF A SUDDEN WILL TURN ON. IT NEEDS TO BE RECALLED. I TOOK IT TO A REPAIR SHOP AND THEY SAID IT WOULD COST AROUND $500 IF NOT MORE TO HAVE THEM TAKE APART MY DASH AND LOOK AND THEN POSSIBLY SEND IT OUT TO SEEIF IT CAN BE FI.XED THERE ARE NUMEROUS PEOPLE I HAVE FOUND ONLINE WITH THIS SAME PROBLEM WITH THE SAME VEHICLE.

NHTSA ODI #10323351

Mileage unknown · May 31, 2009
EquipmentUnknown Or Other

HORN HAS INTERMITTENT ISSUES OF WORKING - WE HAVE TAKEN TO THE DEALERSHIP ON SEVERAL OCCASIONS AND THEN IT WORKS. THEY DO NOT WANT TO TAKE APART THE STEERING WHEEL ASSEMBLY TO RESEARCH THE PROBLEM REGARDLESS OF THE NUMBER OF TIMES WE HAVE HAD THE VEHICLE TO THE DEALERSHIP. NOW THAT THE WARRANTY IS EXPIRING, I AM SURE THE PROBL…

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HORN HAS INTERMITTENT ISSUES OF WORKING - WE HAVE TAKEN TO THE DEALERSHIP ON SEVERAL OCCASIONS AND THEN IT WORKS. THEY DO NOT WANT TO TAKE APART THE STEERING WHEEL ASSEMBLY TO RESEARCH THE PROBLEM REGARDLESS OF THE NUMBER OF TIMES WE HAVE HAD THE VEHICLE TO THE DEALERSHIP. NOW THAT THE WARRANTY IS EXPIRING, I AM SURE THE PROBLEM WILL BE RESEARCHED SINCE IT WILL BE AT OUR COST. THE HORN ONLY SEEMS TO WORK WHEN THE CAR IS FIRST STARTED AND THE STEERING WHEEL IS MOVED SHAPELY. SINCE IT IS UNDER THE AIR BAG, THE DEALERSHIP DOESN'T WANT TO DEAL WITH IT. *TR

NHTSA ODI #10272457

62,000 miles · Apr 21, 2009
Electrical SystemEquipment

TL*THE CONTACT OWNS A 2004 CHEVROLET TRAILBLAZER. THE CONTACT STATED THAT THE SPEEDOMETER STOPPED WORKING AND REGISTERS 65 MPH WHILE THE VEHICLE IS PARKED. THE FAILURE PREVENTS HIM FROM KNOWING HOW FAST HE IS TRAVELING. THE DEALER HAS NOT BEEN NOTIFIED. WHEN THE CONTACT BOUGHT THE VEHICLE, THE SPARE TIRE WRENCH UNDER THE REA…

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TL*THE CONTACT OWNS A 2004 CHEVROLET TRAILBLAZER. THE CONTACT STATED THAT THE SPEEDOMETER STOPPED WORKING AND REGISTERS 65 MPH WHILE THE VEHICLE IS PARKED. THE FAILURE PREVENTS HIM FROM KNOWING HOW FAST HE IS TRAVELING. THE DEALER HAS NOT BEEN NOTIFIED. WHEN THE CONTACT BOUGHT THE VEHICLE, THE SPARE TIRE WRENCH UNDER THE REAR BUMPER WAS STRIPPED SO THAT IT COULD NOT BE LOWERED. HE HAD A MECHANIC EXAMINE THE SPARE TIRE WRENCH AND WAS ADVISED TO TAKE THE VEHICLE TO THE DEALER. THE CURRENT MILEAGE WAS 66,000 AND FAILURE MILEAGE WAS 62,000.

NHTSA ODI #10266236

96,000 miles · Dec 20, 2008
Electrical SystemEquipment

I HAVE 2004 TRAILBLAZER AND CLUSTER IS BAD THIS NEED TO BE RECALL . I NEED TO REPORT A PROBLEM A CAN'T SOLVE WITH GM COMPLAINT NUMBER FROM GM IS 71-683-983-288 AND VIN NUMBER IT WILL COST AROUND 600 TO REPLACED. *TR

NHTSA ODI #10252333

48,000 miles · Jun 26, 2007
EquipmentPower Train

IN APRIL 2007, THE '04 TRAILBLAZER'S TRANSMISSION FAILED. AT THE TIME THE VEHICLE HAD LESS THAN 50,000 MILES. I DRIVE THE CAR VERY WELL - MOSTLY HIGHWAY MILES AS I COMMUTE FOR WORK - AND THE VEHICLE HAD NEVER BEEN USED TO TOW. THE TRANSMISSION WAS REPAIRED AT A CHEVROLET DEALER, AND LESS THAN 2 MONTHS LATER, THE TRANSMISSION…

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IN APRIL 2007, THE '04 TRAILBLAZER'S TRANSMISSION FAILED. AT THE TIME THE VEHICLE HAD LESS THAN 50,000 MILES. I DRIVE THE CAR VERY WELL - MOSTLY HIGHWAY MILES AS I COMMUTE FOR WORK - AND THE VEHICLE HAD NEVER BEEN USED TO TOW. THE TRANSMISSION WAS REPAIRED AT A CHEVROLET DEALER, AND LESS THAN 2 MONTHS LATER, THE TRANSMISSION FAILED AGAIN. I AM VERY UNSATISFIED WITH THE QUALITY OF THIS VEHICLE.*AK

NHTSA ODI #10194259

28,000 miles · Nov 8, 2006
Equipment

2004 CHEVROLET TRAILBLAZER. THE VEHICLE'S A/C AIR OUTPUT WORKS FINE, BUT WHEN YOU SWITCH IT TO HEAT, THE OUTPUT FOR THIS IS DIMINISHED CONSIDERABLY. THE VEHICLE HEATS UP FINE, BUT EVEN WHEN THE AIRFLOW IS ENTIRELY AT THE DASH (NONE DIRECTED TO THE FLOORBOARD) THE OUTPUT OF AIR FOR THE HEAT IS VERY LOW; SO LOW IT CAN'T EVEN BE …

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2004 CHEVROLET TRAILBLAZER. THE VEHICLE'S A/C AIR OUTPUT WORKS FINE, BUT WHEN YOU SWITCH IT TO HEAT, THE OUTPUT FOR THIS IS DIMINISHED CONSIDERABLY. THE VEHICLE HEATS UP FINE, BUT EVEN WHEN THE AIRFLOW IS ENTIRELY AT THE DASH (NONE DIRECTED TO THE FLOORBOARD) THE OUTPUT OF AIR FOR THE HEAT IS VERY LOW; SO LOW IT CAN'T EVEN BE FELT UNLESS THE HAND IS PLACED DIRECTLY IN FRONT OF THE VENT NO MATTER HOW HIGH THE SETTING IS. VEH HAS BEEN TAKEN BACK TO THE DEALER (UNDER WARRANTY), AND WAS TOLD NO DIAGNOSTIC PROBLEM WAS DETECTED; EVERYTHING IS WORKING PROPERLY. COMPARED MY VEHICLE TO OTHERS OF SIMILAR MAKE/MODEL/YEAR, AND DEALER SAYS ALL WORK THE SAME. THIS IS NOT TRUE BECAUSE LAST YEAR, I COULD NOT STAND THE HEAT ON SETTING OF MORE THAN TWO BECAUSE THE OUTPUT WAS VERY GOOD. NOW, IT CAN BE PUT AT A HIGHER SETTING, BUT WITH LITTLE HEAT OUTPUT. I COMMUNICATED WITH AN INTERNET SERVICE TECHNICIAN WHO SAYS IT IS THE AIR FLOW DOOR THAT IS NOT SEALING PROPERLY. THE INTERNET SERVICE TECHNICIAN ALSO SAID IT IS DIFFICULT/TEDIOUS TO FIX THIS PROBLEM. I THINK THE DEALER JUST DOESN'T WANT TO MESS WITH IT AS IT IS UNDER WARRANTY. *NM

NHTSA ODI #10172969

36,000 miles · Sep 6, 2006
Engine And Engine CoolingEquipmentPower Train

I HAVE HAD MY TRAIL BLAZER FOR 1 YR AND 1 MONTH. IN THAT TIME I HAVE HAD TO REPLACE FRONT AND BACK PADS AND ROTORS, BALL JOINTS, CATALYTIC (SP) CONVERTER, AND NOW THEY JUST TOLD ME I HAVE TO REPLACE THE HEAD GASKET ON THE MANIFOLD. WHAT THE HELL IS GOING ON WITH THIS VEHICLE. I NO LONGER FEEL SAFE DRIVING IT. THE OTHER DAY THE…

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I HAVE HAD MY TRAIL BLAZER FOR 1 YR AND 1 MONTH. IN THAT TIME I HAVE HAD TO REPLACE FRONT AND BACK PADS AND ROTORS, BALL JOINTS, CATALYTIC (SP) CONVERTER, AND NOW THEY JUST TOLD ME I HAVE TO REPLACE THE HEAD GASKET ON THE MANIFOLD. WHAT THE HELL IS GOING ON WITH THIS VEHICLE. I NO LONGER FEEL SAFE DRIVING IT. THE OTHER DAY THE RADIO JUST STOPPED PLAYING AND THEN THE SERVICE 4 WHEEL DRIVE LIGHT CAME ON. *NM

NHTSA ODI #10167431

Mileage unknown · Jun 16, 2005
Equipment

TURN SIGNALS INOPERATABLE AT TIMES. BROUGHT TRUCK TO THE DEALER THEY REPLACE A FAULTY HAZARD FLASHER.

NHTSA ODI #10125501

Mileage unknown · Feb 1, 2005
EquipmentFuel System, Gasoline

THE PROBLEM IS THAT MY 2004 CHEVROLET TRAIL BLAZER SPITS UP FUEL BACK OUT OF THE FUEL TANK AFTER FILLING UP THE TANK. I AM NOT TRYING TO TOP OFF. EVERYTIME I FILL UP, FUEL SPITS BACK OUT FROM THE TANK AFTER I REMOVE THE FUEL PUMP. I HAVE TAKEN MY CAR TO THE DEALER TWICE NOW, THEY ARE ON THEIR THIRD ATTEMPT TO FIX THE PROBLEM. I…

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THE PROBLEM IS THAT MY 2004 CHEVROLET TRAIL BLAZER SPITS UP FUEL BACK OUT OF THE FUEL TANK AFTER FILLING UP THE TANK. I AM NOT TRYING TO TOP OFF. EVERYTIME I FILL UP, FUEL SPITS BACK OUT FROM THE TANK AFTER I REMOVE THE FUEL PUMP. I HAVE TAKEN MY CAR TO THE DEALER TWICE NOW, THEY ARE ON THEIR THIRD ATTEMPT TO FIX THE PROBLEM. IT HAPPENED SEVERAL TIMES BEFORE I TOOK MY CAR IN TO THE DEALER. I THOUGHT MAYBE IT WAS THE GAS STATION I WAS USING. SO I TRIED SEVERAL DIFFERENT PUMPS IN DIFFERENT CITIES AND THE SAME THING HAPPENED. THAT'S WHEN I DECIDED TO TAKE THE CAR IN FOR SERVICE.*AK

NHTSA ODI #10108358

Official recalls

2

05V198000 · Exterior Lighting:turn Signal

May 5, 2005

ON CERTAIN TRUCKS AND SPORT UTILITY VEHICLES, THE DRIVER WISHING TO SIGNAL A TURN BY MOVING THE DIRECTIONAL SIGNAL LEVER, (UP OR DOWN) MAY CAUSE THE FRONT MARKER/TURN LIGHTS AND REAR TURN LIGHTS TO FLASH IN A MANNER SIMILAR TO HAZARD WARNING, RATHER THAN FLASHING ON THE DESIRED SIDE ONLY.

Consequence & remedy

Consequence: THE DRIVER MAY NOT BE ABLE TO CLEARLY SIGNAL THEIR INTENTIONS TO TURN, CHANGE TRAVEL LANES, OR POTENTIALLY WARN OTHERS OF AN IMPAIRED VEHICLE OPERATING CONDITION INCREASING THE RISK OF A CRASH.

Remedy: DEALERS WILL REPLACE THE SUSPECT FLASHER MODULES WITH A NEW FLASHER MODULE DESIGNED WITH SEALED RELAYS AND MORE DURABLE CONTACT MATERIAL INSIDE OF THE RELAYS FREE OF CHARGE. THE RECALL BEGAN ON AUGUST 4, 2005. ISUZU BEGAN MAILING OWNER LETTERS ON AUGUST 4, 2005. OWNERS MAY CONTACT CHEVROLET AT 1-800-630-2438, GMC AT 1-866-996-9463, ISUZU AT 1-800-255-6727, BUICK AT 1-866-608-8080, AND OLDSMOBILE AT 1-800-630-6537.

04V527000 · Exterior Lighting:brake Lights

Nov 1, 2004

ON CERTAIN SPORT UTILITY VEHICLES, VIBRATION AND HEAT MAY CAUSE THE TAIL LAMP/STOP LAMP BULB TO LOOSEN IN ITS SOCKET. IF THIS OCCURS, THE BULB MAY FLICKER AND EVENTUALLY BECOME INOPERATIVE.

Consequence & remedy

Consequence: AN INOPERATIVE BRAKE LAMP WILL NOT CONVEY THE DRIVER'S INTENTION OF STOPPING TO DRIVERS IN FOLLOWING VEHICLES, AND AN INOPERATIVE REAR TURN SIGNAL LAMP WILL NOT CONVEY THE DRIVER'S INTENTION TO TURN TO DRIVERS IN FOLLOWING VEHICLES. BOTH OF THESE FAILURES CAN INCREASE THE RISK OF A CRASH.

Remedy: DEALERS WILL INSPECT THE TAIL LAMP/STOP LAMP ASSEMBLIES, AND IF NECESSARY, REPLACE THEM. THE RECALL BEGAN ON NOVEMBER 22, 2004. OWNERS SHOULD CONTACT CHEVROLET AT 1-800-630-2438, OLDSMOBILE AT 1-800-630-6537, BUICK AT 1-866-608-8080, OR GMC AT 1-866-996-9463.

Model-level recall history does not show whether a particular VIN is affected or has received a repair. Check a VIN with NHTSA ↗

NHTSA investigations

4

RQ17002 · Loss Of Headlights

Opened Apr 24, 2017 · Closed Mar 29, 2021

Status: closed (inferred from source dates) · Exterior Lighting:headlights

The subject vehicles are model year (MY) 2002-2009 Chevrolet Trailblazer, GMC Envoy, 2004-2007 Buick Rainier, 2003-2008 Isuzu Ascender, 2005-2009 Saab 9-7X, 2002-2004 Oldsmobile Bravada, 2003-2006 Chevrolet SSR, 2005-2009 Buick Lacrosse, and 2006-2008 Pontiac Grand Prix. This scope includes the Trailblazer/Envoy variants: 2002-2006 Envoy XL/Trailblazer EXT and 2004-2005 Envoy XUV. The original scope of this investigation was expanded to include all vehicles equipped with the subject Headlight Driver Module (HDM). The focus of the investigation was to determine whether actions performed by General Motors adequately addressed any unreasonable risk to motor vehicle safety in the subject vehicles concerning the headlights and the HDM that controls them.Under normal electrical load and environmental conditions, the HDM can overheat inside the Underhood Electrical Center (UEC). This can cause the module to fail and result in a simultaneous loss of both low beam headlights and both daytime running lights (DRLs), often with no warning or prior detectability to the driver. This failure can be intermittent or permanent. No other exterior lights are affected. High beams, turn signals, brake lights, and reverse lights are still operational.General Motors addressed this issue with 2 recalls (14V755 & 15V519) and a special coverage program (N172091910). In view of the recalls and special coverage program implemented by GM and the vehicle high beams continuing to operate, ODI has tentatively concluded that the actions taken by GM mitigate any unreasonable risk to safety posed by HDM failure in the subject vehicles.Accordingly, the investigation is closed. The closing of this investigation does not constitute a finding by NHTSA that a safety-related defect does not exist. The agency reserves the right to take additional action if warranted by new circumstances.The ODI reports cited above are available for review online at NHTSA.gov under the identification numbers in the attached document.

EA07009 · Fuel Pump Module Leaks Gasoline

Opened Jul 10, 2007 · Closed Aug 28, 2008

Status: closed (inferred from source dates) · Fuel System, Gasoline:delivery:fuel Pump

DURING THE COURSE OF THIS EA INVESTIGATION, ODI OBSERVED THAT THE MAJORITY OF THE COMPLAINTS (88%) AND WARRANTY CLAIMS (94%) WERE REPORTED FOR VEHICLES THAT ARE REGISTERED FOR USE IN THE SALT BELT REGION OF THE US.THIS AREA INCLUDES 20 STATES IN THE NORTHEAST, MID ATLANTIC AND THE MIDWEST REGIONS AND THE DISTRICT OF COLUMBIA.CONSUMERS IN THE SALT BELT REGION REPORTED TO ODI THAT THEY COULD SMELL FUEL VAPORS IN THEIR VEHICLES WHILE DRIVING.UPON FURTHER EXAMINATION OF THEIR VEHICLES, THEY DISCOVERED THAT FUEL VAPORS WERE COMING OUT OF THE TOP OF THE FUEL TANK. THIS CONDITION IS CAUSED BY CORROSION OF THE RETURN AND SENDER LINES OF THE FUEL PUMP MODULE.WATER AND ROAD SALT COLLECT ON TOP OF THE FUEL PUMP LEADING TO SMALL PINHOLES APPEARING ON THE FUEL LINES.FUEL MAY LEAK AND COLLECT ON TOP OF THE MODULE AND/OR SPILL ONTO THE GROUND.THE DATA EVALUATED UNDER THIS INVESTIGATION REFLECT A RELATIVELY LOW FREQUENCY OF OCCURRENCE THAT LARGELY ARISES IN SALT BELT STATES.GM HAS EXTENDED THE WARRANTY ON THE SUBJECT COMPONENT TO TEN YEARS OR 120,000 MILES.FURTHER USE OF AGENCY RESOURCES DOES NOT APPEAR TO BE WARRANTED AT THIS TIME; ACCORDINGLY, THIS INVESTIGATION IS CLOSED.THE CLOSING OF THIS INVESTIGATION DOES NOT CONSTITUTE A FINDING BY NHTSA THAT NO SAFETY-RELATED DEFECT EXISTS.THE AGENCY RESERVES THE RIGHT TO TAKE FURTHER ACTION IF WARRANTED BY THE CIRCUMSTANCES.FOR ADDITIONAL INFORMATION SELECT DOCUMENT SEARCH.

EA04021 · Brake Lamp Failure

Opened Aug 3, 2004 · Closed Nov 4, 2004

Status: closed (inferred from source dates) · Exterior Lighting:brake Lights

GM STATES THAT SOME BRAKE/TAIL LAMP BULBS CAN PREMATURELY BECOME INOPERATIVE DUE TO MALFUNCTIONING BRAKE/TAIL LAMP SOCKETS.ON MARCH 2, 2004, GM INITIATED A 6-YEAR/72,000 MILE SPECIAL POLICY FOR 989,487 SUBJECT VEHICLES TO INSPECT AND REPLACE THE REAR BRAKE/TAIL LAMP BULB SOCKET ASSEMBLIES.ON APRIL 4, 2004, THE OFFICE OF DEFECTS INVESTIGATION (ODI) OPENED A PRELIMINARY EVALUATION (PE04-032) BASED ON CONSUMER COMPLAINTS ALLEGING BRAKE LIGHTS NOT OPERATING WHEN THE BRAKE PEDAL IS DEPRESSED.ON AUGUST 3, 2004 ODI UPGRADED PE04-032 TO AN ENGINEERING ANALYSIS (EA04-021).BY LETTER DATED OCTOBER 27, 2004 GM NOTIFIED NHTSA THAT IT WILL CONDUCT A SAFETY RECALL (NHTSA # 04V527) COVERING SUBJECT VEHICLES THAT WERE NOT ALREADY REPAIRED UNDER GM'S SPECIAL POLICY.MY 2004 SUBJECT VEHICLES BUILT AFTER AUGUST 8, 2003 CONTAIN IMPROVED BRAKE LAMP ASSEMBLIES AND ARE NOT INCLUDED IN THE RECALL.GM DEALERS WILL INSTALL THE IMPROVED BRAKE LAMP ASSEMBLY ON SUBJECT VEHICLES BUILT ON AUGUST 8, 2003 AND EARLIER.THE ACTION TAKEN BY GM IS SUFFICIENT TO RESOLVE THE ISSUES RAISED BY THIS INVESTIGATION.ACCORDINGLY, THIS INVESTIGATION IS CLOSED.

PE04032 · Brake Lamp Failure

Opened Apr 6, 2004 · Closed Aug 3, 2004

Status: closed (inferred from source dates) · Exterior Lighting:brake Lights

THE OFFICE OF DEFECTS INVESTIGATION (ODI) OPENED THIS INVESTIGATION ON MODEL YEAR (MY) 2002-04 CHEVROLET TRAILBLAZER VEHICLES.GM REPORTS THAT OTHER VEHICLES SHARING THIS PLATFORM AND BRAKE LAMP DESIGN ARE THE MY 2002-2004 CHEVROLET TRAILBLAZER EXT; GMC ENVOY, XL, XUV; OLDSMOBILE BRAVADA AND 2004 BUICK RAINIER.COMPLAINTS ALLEGE THAT THE REAR BRAKE LAMP DOES NOT OPERATE WHEN THE BRAKE PEDAL IS DEPRESSED.THERE IS NO INDICATION TO THE DRIVER FROM INSIDE THE VEHICLE THAT ONE OR MORE BRAKE LAMPS BULBS ARE NOT FUNCTIONING.GM FOUND THAT HEAT FROM THE BULB COULD DEFORM THE LAMP SOCKET, PRODUCE ELECTRICAL ARCING AND AN INOPERATIVE BULB.TO CORRECT THE CONDITION, GM CHANGED THE BULB TO A BULB THAT TRANSMITS LESS HEAT TO THE SOCKET AND CHANGED THE SOCKET TO A THERMOPLASTIC POLYMER TO IMPROVE THERMAL STABILITY.THESE CHANGES WERE IMPLEMENTED INTO PRODUCTION VEHICLES ON OCTOBER 1, 2003.GM IMPLEMENTED A SPECIAL POLICY BY NOTIFYING CONSUMERS THAT IF THEY SHOULD EXPERIENCE A BRAKE LAMP FAILURE TO GO TO THEIR GM DEALERSHIP TO HAVE THE CIRCUIT BOARD CONTAINING THE BRAKE LAMP REPLACED ALONG WITH NEW BULBS.THIS POLICY IS GOOD FOR THE FIRST 6 YEARS OR 72,000 MILES OF THE LIFE OF THE VEHICLE.ODI WILL UPGRADE THIS INVESTIGATION TO EA 04-021 AND INCLUDE THE ABOVE MENTIONED VEHICLES.